when the status quo frustrates.

Governments interfering in education? Oh no!

Monday, September 17th, 2007

When the U.S. government makes changes to the public education system, forcing public schools to conform to state regulations or face privatization, it’s business as usual.

When the Venezuelan government makes changes to the private education system, forcing private schools to conform to state regulations or face nationalization, it’s a Socialist! School! Takeover!

Speaking of standards, 11% of Americans can’t find their own country on a map. Meanwhile, the education system under Chávez seems to be vastly improving. (I couldn’t find any information on Venezuelan map-reading abilities. One can only assume that they know where donkeys come from.)

I can only assume that the new Venezuelan history textbooks won’t be as bad as the ones we had in public school. Each chapter brimmed with gushing descriptions of white, upper-class male accomplishments, with a paragraph here and there about “the role of women,” and barely a whisper about the folks from whom we stole this land.

17.09.2007 Edumakashun, book larnin' 3 Comments

Education: big mistake or bad idea?

Sunday, September 9th, 2007

“How much are YOU WORTH?” A shady computer tech school in my area begins their radio commercials asking people to pause and reflect on that question before going on to imply that a certification in information technology will be worth about 50K right at graduation, and creating a false sense of prestige by saying you have to pass a test (oh, god, not a test!) to qualify for their program. For a person stuck in some of the armpits of service jobs we have here, such an offer must sound pretty tempting – I know that at my least employed and most desperate I spent $200 on a bartending course that was laughably useless although by the time I was willing to admit that, the check had already cleared and the classroom had moved on to the next geographical set of suckers. I keep the certification just to remind myself that I’m not as smart as I think I am.

I thought about that a few days ago when Cog over at Offsprung touched a nerve on the topic of useless vs useful college degrees. Cog, who I guess got burned by his expensive but ultimately not lucrative undergraduate program, subscribes to “the idea of college is to spend lots of money to get a degree that will get you a job.” A view that drives others (like me) insane. By the middle of the thread, it was very clear that this was a highly personal subject that divided people into roughly three or four camps that were speaking different languages. And I thought about it when I ran into today’s MSN list’o'the hour, Top Earning College Degrees.

Of the top 10 starting salaries according to major, no fewer than five have the word “engineering” in them. Two or three others (depending on how you count economics) involve high finance, and the remaining ones are computer related. Unifying theme? Math, and plenty of it. And they’re freaking hard.

The participants in Cog’s conversation were heavy on the liberal arts degrees, no shock since college graduates in general are heavy on the liberal arts. As far as I can tell, they divided into camps roughly along these lines:

1) Cog’s Supporters: People who feel that since the conventional wisdom is that you need a degree to get a decent job then you should pick your major based on lists like the one offered by MSN to ensure that you’re not burning money.

2) People who feel that education is it’s own reward.

3) Sensible Educational Theory types, who’d like to agree with statement 2 but have been crushed by reality and would like us hoity-toity learn-for-the-love-of-it types to wake up to the real world, kids.

I belong to group 2, but I have to admit to being a bit of a hypocrite; I ended up trading a kind of joke major for a more impressive, and more reliably lucrative, one. You see, my original major was communications, which I studied at a University that cost as much per year as three or four years at the place I ended up graduating from. So really, I almost made the same costly mistake that Cog appears to think he made. But by the end of that year I was bored out of my mind, I hated the school, and I realized that for what I wanted to do, college was the complete wrong path.

So I quit, and spent a year in theatre, doing some prop stuff and stagehand stuff. But when I realized that I could -if I was lucky and worked my ass off- maybe someday have my boss’ job, I quit that too. I went back to school but this time I majored in physics, and it took 5 years which basically sucked the whole way through. But then I got my degree and it really was the magic piece of paper everyone thinks a college degree is, and I’ve been doing pretty OK ever since.

So with that disclaimer out of the way, I’d like to use this thread to sort out some confusion I saw between the camps in Cog’s thread, because it seems that a lot of people were talking over each other. The whole thing has a tawdry Mommy-war vibe to it, with opposing camps that each have really good points but are defensive and see only where they disagree. So let’s open this can of worms with an insanely long post!
(more…)

09.09.2007 A million ways to mortgage the future, Blogitics, Circle Jerking, Conformity, Culture, Edumakashun, Politics, Purposefully Inflammatory, Soapbox, book larnin' 18 Comments

I’d save even more if they’d let me buy by the pound.

Saturday, August 18th, 2007

Two classes outside my major department* and already I’ve spent $250. Thank God for the internets, because at the bookstore I’d be looking at something closer to $400.

I just hope that second class doesn’t get canceled.

*This is actually relevant. In my field my professors write their share of the textbooks, so well over half the time they just print notes out or post them on the intranet. I buy the hardcopy anyway when it’s available, but that means I’ve purchased 2 books the whole year. These classes in other departments require two books per class.

18.08.2007 Asides, book larnin' 1 Comment

Why the sky is blue and snow is white

Monday, August 13th, 2007

Sure, you can tell your kids that it’s a reflection off the ocean, but this will really get them to shut the hell up.

Both colors are a result of light scattering, or when light hits something that can reflect it back in many directions. This is the difference between a nicely polished mirror and a pile of crushed mirror dust. One gives you a nice reflection, the second is a glittery mess. The glittery mess is a result of the light scattering.

scatter
A zillion tiny differences in the angle of incidence leads to scattering

The sky

The sky is blue due to a phenomena called Rayleigh scattering. Lord Rayleigh was an old school physicist who got a lot done, and gets many things named after him (his name also would have come up if anyone had cared to know how ink jet printers work, even though he lived and died ages before Canon Inkjets). Rayleigh scattering is an approximate description of how light gets scattered when it hits a small particle, say, nitrogen gas (N2). We’re talking small small, like so small that the wavelength of light (approx. 400-700 nm or 0.0000157 – 0.0000276 inches) matter, and matter a lot.

For unpolarized light (like from the sun) the intensity of light subject to Rayleigh scattering can be described by this equation, which I just stole from Wikipedia because it’s way cooler than the version I have in my notes:

I = I0*(1 + cos2(theta))/2R2 * (2pi/lambda)4*((n2-1)/(n2+2))*(d/2)

Where I0 is the original intensity, theta is the scattering, R is the distance to the particle, n is the refractive index, lambda is the wavelength in question, and d is the particle diameter. So for a particle of N2, I0, n and d are constant, cos2(theta) varies between 0 and 1, so that leaves us with R and lambda as variables of importance. I is inversely proportional to both, with I proportional to 1/R2 and 1/lambda4. The 1/R part tells you that the farther you are from the source (scattering particle) the weaker the light is. If I’m 1 unit away, I = AI0, where A is the rest of that shit. If I’m two units away, then I = (1/4)AI0. 3 units, I = (1/9)AI0 and so on. That’s pretty boring.

So let’s look at the other term: 1/lambda4, or 1/(lambda*lambda*lambda*lambda). That’s a lot of damn lambdas. The intensity really gets to feel every little change in lambda. If lambda = 1, then I = I0. But if lambda = 2, then I = (1/16)I0. Lambda should be measured in the same units as R and d (in fact, take a moment to notice that there is R2 and lambda4 dependence in the denominator, and d6 dependence in the numerator. If you measure R, lambda, and d in the same units, say meters, then you end up with meters^6/(meter^4*meters^2) = meters^6/meters^6 = unitless. The rest of the factors (cos(theta), n) are also unitless, because the whole mess is just a factor that reduces I0. If your units don’t cancel, then you turn I into I*m or something equally meaningless. The process of using units without numbers to make sure your answer will result in the proper form is called unit analysis, and is quite handy during exams when you’ve forgotten an equation).

Since I is proportional to lambda to the fourth power, any increase in lambda will result in a significant decrease in I. This means that longer wavelengths will scatter less than shorter, blue scatters more than red.

The snow

Snow is actually very simple compared to the sky. It’s got much more in common with our easily understood crushed mirror. Snow consists of snowflakes, which are crystals of ice with gaps of air. So a pile of snow is basically a skajillion bajillion umptillion fine icecubes with some space in between. We’ve already discussed, at great length, index of refraction, n. The ice has a larger n than the air, so the light will bend a decent amount as it passes through the many interfaces of air and ice.

So light hits a snow crystal, and some bounces off the top. But some goes through, and hits the other side, where it bounces off that, but some goes through and hits the next ice piece at a slightly different angle and bounces off of that, but some goes through and…you get the picture:

scatter2
A single ray of light bounces through some snowflakes, simplified picture. Obviously the first reflection is the brightest, and the next ones get significantly weaker. But that’s OK, because there’s more than enough incident light for all of our light scattering needs

The end result is a glowing, sparkling, uniform white.

13.08.2007 Punkass!, book larnin' 9 Comments

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